chore: fix failing mk*Sorry in bootstrapping contexts (#9950)

src/Lean/Elab/Term.lean

@@ -1188,9 +1188,8 @@ private def mkSyntheticSorryFor (expectedType? : Option Expr) : TermElabM Expr :
   elaboration step with exception `ex`.
 -/
 def exceptionToSorry (ex : Exception) (expectedType? : Option Expr) : TermElabM Expr := do
-  let syntheticSorry ← mkSyntheticSorryFor expectedType?
   logException ex
-  pure syntheticSorry
+  mkSyntheticSorryFor expectedType?
 
 /-- If `mayPostpone == true`, throw `Exception.postpone`. -/
 def tryPostpone : TermElabM Unit := do

src/Lean/Meta/Sorry.lean

@@ -38,6 +38,9 @@ Returns `sorryAx type synthetic`. Recall that `synthetic` is true if this sorry
 See also `Lean.Meta.mkLabeledSorry`, for creating a `sorry` that is labeled or unique.
 -/
 def mkSorry (type : Expr) (synthetic : Bool) : MetaM Expr := do
+  if !(← hasConst ``sorryAx) then
+    -- Abort if we are not ready yet to generate `sorry`s in bootstrapping contexts.
+    Elab.throwAbortCommand
   let u ← getLevel type
   return mkApp2 (mkConst ``sorryAx [u]) type (toExpr synthetic)
 
@@ -77,6 +80,9 @@ Constructs a `sorryAx`.
 * If `unique` is true, the `sorry` is unique, in the sense that it is not defeq to any other `sorry` created by `mkLabeledSorry`.
 -/
 def mkLabeledSorry (type : Expr) (synthetic : Bool) (unique : Bool) : MetaM Expr := do
+  if !(← hasConst ``Lean.Name) then
+    -- Abort if we are not ready yet to generate `sorry`s in bootstrapping contexts.
+    Elab.throwAbortCommand
   let tag ←
     if let (some startSPos, some endSPos) := ((← getRef).getPos?, (← getRef).getTailPos?) then
       let fileMap ← getFileMap

tests/lean/bootstrapSorry.lean

@@ -0,0 +1,8 @@
+module
+
+prelude
+import Init.Prelude
+
+/-! Trying to generate a `sorry` should not itself lead to errors in bootstrapping contexts. -/
+
+public abbrev Foo := Nat

tests/lean/bootstrapSorry.lean.expected.out

@@ -0,0 +1,3 @@
+bootstrapSorry.lean:8:21-8:24: error(lean.unknownIdentifier): Unknown identifier `Nat`
+
+Note: A private declaration `Nat` exists but is not accessible in the current context.